摘要
为了合成理论预测存在的高密度氮化碳相,以富氮的C-N-O非晶材料和晶态的双氰胺为前体,在低于50 GPa的冲击压力范围内进行了一系列冲击回收实验。回收产物的XRD衍射表明,形成了由β-C3N4和一种新的氮化碳相组成的复合相。该新相的衍射峰可以完全指标化为一个单斜晶胞,晶胞常数为a=0.981 nm,b=0.723 nm,c=0.561 nm,β=95.2°,晶胞体积Vcell=0.396 6 nm3。根据实验结果可以认为,氮化碳复合相的形成是前体有机分子在瞬态的冲击波化学反应后,经历了极高速的冲击淬火过程(约109K/s),作为一种高压亚稳相而被保存下来。冲击压缩富氮的有机物前体,是合成氮化碳相的一种新方法。
To synthesize a carbon nitride with high density existing by theoretical prediction, a series of shock recovery experiments up to ≈50 GPa were carried out on two nitrogen-rich materials of a C-N-O amorphous precursor and dicyandiamide. The powder X-ray diffractions （XRD） of recovered samples show that the carbon nitride composite phases are formed consisting of β-C3N4 and a new crystalline phase. The new phase is indexed as a monoclinic cell with α=0. 981 nm,b=0. 723 nm,c=0. 561 nm,β=95.2° and Vcell=0. 396 6 nm^3. We considered that this new phase is formed to survive as metastable species by extremely high quenching rate （≈10^9 K/s） after transient shock-induced reaction of these organic precursors and so shock compression may provide a novel synthesis route for various carbon nitride phases from appropriate rich-nitrogen organic materials.
出处
《高压物理学报》
CAS
CSCD
北大核心
2006年第1期20-24,共5页
Chinese Journal of High Pressure Physics
基金
日本国立材料科学研究所探索研究计划的支持.
关键词
氮化碳
冲击波合成
亚稳相
carbon nitride
shock wave synthesis
metastable phases
